Boss DS-1 Keeley Mod

I Just did the Keeley mod to my DS-1 and the LED I used for D5 is not lighting up when I play. What could cause this? I modded one about two years ago and it lit up perfectly fine.

What value resistor did you use for the LED? Also, did you install the rresistor to the correct leg of the LED?

What value resistor did you use for the LED? Also, did you install the rresistor to the correct leg of the LED?

It's not actually the indicator LED. It's an LED used as a clipping diode. D5

Is the LED oriented properly? Try reversing the connections to it's legs. They only conduct in one direction.

Is the LED oriented properly? Try reversing the connections to it's legs. They only conduct in one direction.

Yep it's the orrery direction! negative to negative and positive to positive. The pedal even works and sounds good! just no light..

How would one go about doing this mod exactly?

How would one go about doing this mod exactly?

It's what Brian Wampler posted in his book as Robert Keeley's DS-1 mod:

C1 - .1uf
C2 - 1uf
C5 - .1uf
C7 - 220pf
C8 - 1uf
C9 - 1uf
C12 - .1uf
C14 - 1uf
R14 - 1.5K (I did 10K so as to lower the gain)
R35 - 2.4K
R39 - 20K
D4 - LED
D5 - LED and 47pf cap in series


R14 is 2.2K stock. If you lower it to 1.5K it will raise the amount of distortion. I chose to raise it to 10K so as to lower the distortion.

Yep it's the orrery direction! negative to negative and positive to positive. The pedal even works and sounds good! just no light..

OK, try taking R14 back down to 1k5 or 2k2 and see if it lights up. Then you can raise R9 a bit to lower the gain. 100 ohm works well for me. Try 47 ohm if that's too big a cut.

Awesome! I'll give it a try. Thank ya!

It's not actually the indicator LED. It's an LED used as a clipping diode. D5
if the LED you're talking about is setup as a clipping diode chances are it's not going to light up. Diodes generally don't light up when used for clipping and whether it does or doesn't if it works what does it matter.

if the LED you're talking about is setup as a clipping diode chances are it's not going to light up. Diodes generally don't light up when used for clipping and whether it does or doesn't if it works what does it matter.

^ Thats true....unless you drill a hole in your Boss pedal specifically to see your clipping led light up.:shock:
While that was pretty mind blowing 15 years ago:roll: I think the novelty has run its course.:lol:
Just teasing, to each his own!

D5 - LED and 47pf cap in series

That's why your LED won't light. :lol: